Relieving machine



Jan., 3o, 1923.

F. MLLER. REUEVING MACHINE, OR|G|NAL FILED MARV 1.19.19 5 SHEETS-SHEET lH QN EN u umm n Jian. 3o, 1923.. 1,443,639

. F. MULLER.

RELIEVING MACHINE. ORIG NAL F1 LED MAR. 3l 1919. 5 SHEETS-SHEET 2 Jan.30,' 1923.

F. M'LLLER RELIEVING MACHINE ORIGINAL FILED MAR.

5 SHEETS` SHEET 3 www Jan. so, 1923. 1,443639 F MULLER RELIEWNG MACHINE.OmGlNAL FI LED MAR 3l 1919 5\ sHEETs-sHEET 4 Jan. 30. 1923.

srss

FRIEDERICH MLLER, OF HARTFORD, CONNECTICUT, ASSIGNOR '.ll PRATT & WHIT-NEY COMPANY, F NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

RELIEVING MACHINE.

Original application led March 31. 1919, Serial No. 286,524. Divided andthis application filed May 13,

To all 707mm may conce/'fn' Be it known that I. Funnix-mou MiLLER, a.citizen of the United States. residing at Hartford. in the county ofHartford and State of Connecticut. have invented certain new and usefulImprovements in Relieving Machines, of which the following is aspecification.

My invention relates to relieving machines and particularly to relievingmachines for .operating on cut-ter blanks having teeth provided withnon-radially arranged cutting faces.

One object of my invention is to provide a machine that shall cuta blankto a rectilinear or to a non-rectilinear contour while effectingrelieving movements ofthe cutting tool and compensating such relieving'movements'at different blank diameters for the non-radially arrangedcutting faces on the teeth of the blank.

Another object of -my invention. is to provide a. machine of the aboveindicated char acter that shall be'V provided with a pin and a. formerfor guiding a cutting tool to cut the blank to a redetermined contour,means for effecting re ieving movements of' the tool to relieve theteeth of the blank in conformity either to helical or straight teeth,and means for so varying the relieving' movements as to compensate atdifferent blank diameters for non-radially arranged cutting faces on theteeth of' the blankl A further object of my invention is to feedingmovements` between the cutting tool and the blank, means for stoppingthe blank rotation during' each feeding movement, means for effectingtransverse movements of the cutting tool to permit the intermittentfeeding movements. means for effecting rclieving movements'of' the tool.and means for varying the `relieving movements to com pensate atdifferent blank diameters` for the non-radial cutting' faces on'theteeth of' the blank.

In the art of cutting many materials and particularly in cutting metals.it is preferable for many classes of' work to incline the face ot' the'cutting tool backward with respect to the direction of'movemnt thusproprovide a relieving machine with mccha-. nlsm for efi'ectlngintermittent longitudinal' Serial No. 469,267.

viding a rake or undercut which provides a sharper cutting edge andenables other ad vantages t0 be obtained. To a very limited extent thisprinciple has been applied to milling-cutters, theA cutter faces 'beinginv clined backward Iwith respect to radial lines, but it has not,heretofore, been deemed possible to cut a milling cutter to differentdiameters in accordance with a predetermined contour and to effectrelieving movements so that the teeth can be ground on the cutting facesWithout changing the effective Y 'contour of` the blank. If the cutteris cut t0 more than Ione diameter and the teeth have faces which areundercut oi' non-radially arranged, it essential while cutting the blankto compensate the relieving' operation at the different blank diametersfor the non.- radial cutting faces on the teeth.

'lhis application is a division of the ap-t .plication Serial No.286,521. filed March 31,

eov

specific methods disclosed in this applicav tion are specificallyclaimed in 'my copending' application Serial'No 323.112, filed Septcmber11, 1919. The machineA disclosed in this application is adapted to forma cutter such as is described and claimed in my copcnding applicationSerial No. 323.110 filed September 11. r1919.

'.l`he cutters. which are shaped by the relieving' machine disclosed inthis application, are adapted to cut any practical contour. llach cutterblank is cut. to diderent diametersand is adapted to cut eitherarectilinear .or a non-rectilinear contour. The cutting teeth on theblank are either helical non-radially arranged cutting faces. In

case the teeth are helical in for-m, the cut-v lines extending backwardand inward t'roin ting tace of each tooth conforms to a heli cold. Thehelicoid is formed by a gene 'atrix following a helix on a smallcylinder concentric with the axis of `the cutter and also following ahelix on a much larger cylinder also concentric with the axis. The teethof the cutter and t-he cutting faces may he inclined in either directionwith respect to the axis and the degree of inclinotion may be varied asrequired.

Each tooth of the cutter is relieved along the outline of the'non-radialcutting lace. The relief lines form a continuous surface or continuonssurfaces which extend from end to end of the cutter. The relief linesare properly constructed notwithstanding variationsin radius at.difierent points along the outline ol' the cutter and notwithstandingtli'e variations in angular positions resulting from the non-radialhelical ciittiiig.l':ice. Preferably, the relief lines are maintainedin'siniilar relationship to each .other as they extend backward andinii'arihtbe lines conforming to spirals ot'- Archimedes.

lVhen the relief lines contorni to spirals and are maintained in similarrelationship as they extend backward and inward. as is preferred, it ispossible to sharpen or grind the teeth otl the cutter on the ir'ontcutting faces without changing the eli'ective contour. The teeth presentthe same etlective contour at successive non-radial helicoidal surlfacesof intersection Similar in torni and position to the initial cuttingfaces. At any surfaceback ot the initial cutting face and similar l tosaid tace, the saine eti'ective contour will be found. Therefore, it'the teeth arc ground on their front Faces to non-radial .helicoids whichare the same as the nonradial helicoids ot' the .initial cutting taccs7the elllective contour will remain the same.

ln the accompanying drawings:

Figure 1 is a, partial trout elevational View, partially insection, ol:i machine con- `str-acted in accordance with my invention.'

Fig. Qlis a partial plan view of the niachine showing the tool-carryingslides.

Figs. il and 1i are detailed `views ot' the ymechanism for varying themovement ofthey blank carrying spindle. the, views being taken fromopposite -sides of the machine. Fig. 5 is an end view ot the machine.`Fig. t3 is transverse vertical sectional View taken along the line l---of Fig. l.

Fig. T a vertical longitudinal sectional i i'iew of the machine.

Fig. 11 is a transverse vertical sectional View taken along the liliesll-ll of Figs. 1. i2 and 7.

Fig. 12 is a transverse vertical sectional View taken along the lilies12-12 ol' Figs. 1. 2 and "T.

Fig. 12% is a tragmeiitar)l longitudinal scctional vie along the. linesl-l 13 of Figs. 2 and 11.

Fig. 1l is a fragmentary transverse sectional view taken along the linesHwldfkk ol Figs. 3 and 4.

Fig. 15 is a transverse sectional view taken along the lines 15-15 ot'l"ig. 4. v

Fig, 16 is a partial rear view, partially in section. ot the machine.

Figs. 1T. 1S and 15) are diagramiiiatiil views illustrating theoperation that is l'ollowed in operating on cutters having nouradiali).`arranged cutting laces.

Fig. 2l) is a fragmentary sectional view .similar in )art to Fie. 11.

Fig. 21 is a development view member shown in Fig. 2o.

Figs. 22. )l and 24 are diagrammatic views showing the relation betweenthe. former members and the blanks for cutters provided withnon-radially arranged cutting faces.

llel'erring 1o the drawings. a relieving niacliintl is provided with amain trame or bcd l upon which the other parts of the machinearemountcd. headstock :2 anda tailstock il are provided l'or carryingthe blank which is to be operated on. tool holdiugand-op4 eratiugmechai'iism l is provided. as shown in Fig. l. lrelerabliY the hcadsiock2 and the tailstock Il are so arranged as lo hold the blank againstlongitudinal movement. the tool mechanism l being moved longitudinallyalong the blank in the lmanner to be pres` cnlly set l'ortli. ll'hcn themachine is so constructed. tlielicad stock :2 is lixedly sc Cured to thebed. preferably being formed in part integrally therewith. as shown.'l`lie tailstock 3 is adjustable along thc bed to accommodate blanks orblank arboi's ol dil"- leirxent lengths. y

ihe hcadstock 'l olI thc caui is provided with a rotatable spindlemounted in suitable bearings (i and T. Secured to thc spindle 5. in anysuitable manner. is a collet chuck H ,which may be ol' any usual orprcl'errcd form and which is adapted to grip either the shank ot' the.tool to be formed and relieved or an arbor upon which -the ,tool ismounted. As illustrated. there is a blank A mounted upon an arbor l. thearbor being engaged by the chuck H. A drivenicclianism including adriving member in the l'orm ot ay worin wheell) which meshes with a worml() on a transif'erse rotatable shaft ll. is provided foi rotating thespindle 5.

The tailstock 3 may be of any usual or l preferred construction, and isadjustable v.along waysv 12 and 13. The tailstock 3 can besecured inadjusted position by means ot .',alamp 14 which is controlled by a lever15. f fhenftailstock vspindle 16, which carries a fnter '17,' can bemoved longitudinally by vmeans of-.ascrew 18'under the control of a handWheel 19. A handle 20 is prov1ded'for clamping the sleeve inv adjustedposition.

shown'in Fig. 2, the center 17 is adjusted in engagement with the end ofthe 'abor B.

,'.The tool Amechanism 4 includes a carriage a'nd such a tool ispreferable for .many

classes of work.v However, the invention is ,',Ilot limited tomanon-rotary tool and when `preferred a rotaryltool can be used. The 'tool25 iSpreerably very narrow, but if desireda wider tool can be used whencon- ',s'tructed inaccordance with the method set .forth inmy Patent No.1,348,302 dated August 3, 1920.

`As stated at the outset, a machine embodying the invention is adaptedfor cutting va blank having4 a varyingdiameter. rl`he diameter may varyuniformly from end to -end of the'blank, thus providing a uniform taper,or it may vary in any desired wayso as to provide the. blanklwith anypredetermined contour differing from a straight line.` The variations inthe diameter ot' the blank `are determined by moving the sl'de 24 to'-gether with the tool transversely` and pret'- erably, for regulating andcontrolling the transverse movements, I provide a former and a formerpin, one carried in fixed position on the bed 1, and tlie other carriedby the slide 2 4. As illustrated, a former 26 is carried by the bed 1and a former pin,27 is carried by theslide 24. rl`he former 2G hasexactly the same contour with which the blank is to he formed and theformer .pin 27 has exactly the same shape the cutting tool 25. The pinis detachably secured to the slide, in a. manner to be hereinafter setforth. so that it can be removed and another pin be substitutedcorrespomling to atool differing in shape trom the tool 25 which isshown. A bracket 28, which is rigidly secured to the bed 1, is providedfor supporting the former 2G.' In order to permit adjustment, the former26 is secured to a slide 29 which is longitudinally movable along asuitable guideway 3() on the bracket. a screw 31 beingr provided toreffecting longitudinal movement. The slide can be locked in ad- "justedposition by means-of screws $52. 32 which engage a gib 33. rThe slide2S) is provided with a T-slot 34 which is adapted to receive -T-bolts-35 passing through the former. Such arrangement is provided to permitthe ready adjustment of the former. To Jf'urther assist in holding theformer in place and to prevent any possible Jree movement thereof, ahooked bolt 3G is provided which.'when tightened, serves to draw theformer back against a suitable shoulder on the slide. ln practice, aformer 26 is selected having the contour with which the blank A is to beformed and then by means of the slide 29 the former is adjustedlongitudinally until it bears the same relation toy the former p'in 27that the blank A bears to the tool 25. As the carriage 2l is movedlongitudinally the slide 24 with the tool is moved transversely so as tokeep the former pin 27 in engagement with the former 26.

ln order that the tool may be given arelieving movement to prope'rlyrelieve the several teeth on the blank, it is 'not rigidly secured tothe slide 24 but is transversely movablev thereon. A slide- 37, which istransversely movable along a suitable guideway, is mounted on the slide24. A mecha` n'sm, for effecting regular reciprocating relievingmovements ofthe slide 37 and the tool in suitable timed relation withthe rotative movement ot' the blank vis carried in part by the slide 24.ln order thatl the tool may be adjusted tor blanks of diti'erent sizes7a tool-carrying slide 38 is provided which is transversely movable onthe slide 37. A screw 3S) which is rotatedby means of a hand wheel 4l),is provided for moving the slide 38. The slide 38 is provided with atransverse T-slot 41- and a tool post 42 is held in place by means ot'T-bolts 43 entering the slot 4l. The tool post has a toolrecewingaperture provided with a` horixontal top wall 44 exactly at the level ofthe axis ot' the blank. 'lhe tool 25 is positioned with its top surfaceengaging the horizontal wall 44 of they tool post. and is held in this"feeding or inward and outward to follow' the contour.

llO

The relieving mechanism for moving the I lower end is provided with aroller engagf ing the cam 4G. The upper end of the'lever engages anabutment 52 on the slide r.37. A'coil spring 53 is interposed betweenthe slide 37 and the slide 24. this spring tending ,in a bearing topress the slide 37 forward. thus holding: the abutment 52 in firmcontact with the upper end ot' the lever 5l. lt .vill be seen that. whenthe cam 46 is rotated, the lever 5l will be oscillated, thus giving' are ciprocating movement to the slide 37 and to the tool 25. The shapeofthe cam 46 is such that the slide 37 is moved forward relativelyslowly at a uniform rate so that the tool may etl'ect a relievin, r cut.and then drawn back relatively rapidly so as to withdraw the tool andposition itJ for another eut.

'l`he cam hlo is driven in timed relation with the blank rotation. asbefore stated. For rotating the cam. l make use of the aforesaidtransverse shaft li. A shaft 54, which is mounted partl'v in the mainframe l and partly in a l 'acket 55 secured thereto. is positionedinnnediatel)Y below the shaft l1. 'lhetwo shafts 1l and o lare connectedb v means of a gear wheel on on the shaftA ll. a gear wheel :'17 on theshaft 5l and an idler gear wheel 5H meshing` with the two xrear wheels5G. and 57. rl`he idler gear wheel is mount-ed on a bearinzgr sind 59which is carried b v an adjustable slotted arm (SO. The arm (S0 iscarried b v a hub (3l which assists in supporting' the shaft l1. Thespeed ratio between the two shafts ll and can be changed b v removing'one or both off the gear wheels 5G and 5T and substitut;- in; other gearwheels of different diameters. it being clear that the idler j fearwheel 58 can be adjusted to mesh with such diiferentl'v diameter-ed`'ear wheels. vertical shaft` ('12 is mounted in the bracket 55 and isdriven from the shaft 54 by means ofv bevel gearing` ('13. rl`he shaft(v serves to drive a loinfitinliiiallv lsplincd shaft (i5 by means ofbevel gearingr (il. rThe shaft is supported partlyv in a bearing onsecured to the bed and partly in bearings (37 on a depending bracket (3Ssecured to the car riage 2l.

worm o9. which isnuounted on the shaft (i5 between the bearings G7, issplined to the shaft. The worm 69 meshes with a worm wheel 70 which isconnected with a transverse shaft 7l. The 'worm wheel 7G and the shaft7l are rotatably mounted in a bearing 72 Aformed in the bracket 68, andI72 formed on a supplemental bracket T4 secured to the bracket (3S. ii.bevel gear wheel 75 is slidablvY mounted on the shaft 7l and is engagedby a bearing Tt on the aforesaid bracket 5() depending from the frontend ot 'the slide The bevel gear wheel 75 and the shaft Tl are connectedby means of cani slotsTl formed in the sha ft and pins 75 proiectinj rfrom the gear wheel into the cam slots so that, the bevel gear wheel isrotated. but is at 'the saine time free to move transversel)v of themachine when the slide 24 is moved. The cam slots 7l' in the shaft 7lare so formed as to compensate the relieving movements .atdiil'erentblank diameters for non-radial cuttin r faces. The operationof the pins 75 in the cam slots Tl will be set forth more fullyhereinafter. Inasmu'ch as the bevel gear wheels 75 and 77 are bothsupported by the bracketl 50, they are at all times held in mesh. Itwill be seen that with this construction power is transmitted from theshaft 1l, through the several parts that have been described, to theshaft 65, and is transmitted from the shaft 65 to `the shaft l? and thecam 46, the connection between the shaft and the shaft 47 being suchthat tree transverse movements of the cam and associated parts ispermitted. The cam lo is given one -complete Yrotation for` cach toothot' the blank. The machine ain be adjusted for blanks with differentnumbers ol teeth b v changing the gear Wheels 56 and 5T. as alreadyexplained.

has already been stated. the machine is adapted for cutting blankshaving helical teeth. ln order that blanks with such teeth may beproprely relieved, it is necessary to etl'ect the relieving movements ofthe tool in peculiar relation to 'the rotative movement of the blank sothat the relief may be in conformity with the helical teeth. I havestated that the relieving movements of the tool are effected in timedrelation to the rotative movement of the blank; and, for any givenposition of the carriage, this timed relation .is fixed and definite.but when the earriage is moved to bring;r the tool into a new cuttingrposition. it. is necessary to vary the relation between the relieving,rmovements ot the tool and the rotative movement of the blank. For thispurpose I make use of a. mechanism which is in many respects similar tothat set fort-h in my aforesaid Patent 1,420,611. however. in that lhave so arranged the mechanism that the aforesaid relationship is variedby changing the rotative movementof the blank rather than by changingthe relieving movements of the tool. Vhile l prefer to `change the blankrotation, it will be understood that my present invention in its broaderaspects is not limited in this respect.

ln the construction illustrated` the driving The present constructiondiffers,"

member or worm wheel 9 is not connected dibearing in the outer end ofthe spindle 5. A frame 82 is recessed to receive the outer end of thespindle 5 and to engage the outer surface thereof. The aforesaid wormWheel 9 is rigidly secured to the sleeve 79. A shaft 83 having rackteeth formed thereon at 84 is slidably mounted in the sleeve (9.' T heshaft 83 is splinedto the sleeve9 so as to be -rotatable therewith. Atransverse shaft 85 which carries a. pinion 86 meshing with the rackteeth 84, is-rotatably mounted in bearings in the frame 82. A transverseshaft 8T is also rotatably mounted in the frame 82. The two shafts 85and 8T are connected by spur gear Wheels 88 and 89. 'A third rotatableshaft 90 is rotatably mounted in the frame v82. A Worm 91, Whichmesheswith Worm teeth 92 formed in the periphery of 'the spindle 5` near theend thereof, is secured to the shaft 90. A gearing is provided at the'side of the bracket 82 opposite from the gears-88 and 89 for connectingthe shafts 87 and 90. A gear Wheel 93 is mounted on the. shaft 87, and agear wheel 94`is mounted on the shaft 90. An adjustable slotted bracket95 is mounted on the frame 82 and this car# ries adjustable bearingstuds 96 and 9T on which are mounted, respectively, idler gear wheels 98and 99.

An annularly grooved collar100 is carried by the shaft 83 near the outerend thereof. A longitudinal guide stud 101 is rigidly secured to themain frame 1 adjacent the shaft bracket 102 having a fork 103 enteringthe groove in the collar 100 is slidably mounted on the stud 101. Thebracket 102 is apertured to receive a longitudinal rod 104, which isconnected at its right-hand end with the carriage 21'. The bracket`102may be clamped to the rod 104 in any desired relative position andpreferabl f by means of screws 105, 105 provided with andles 106.

It will be seen that, when the carriage 21 is moved longitudinally alongthe bed, the rod 104, together with the bracket' 102, will be moved atthe same time and to the same extent. ly reason of the engagement of thefork 103 with the collar 100 the shaft 83 is similarly moved,thus'moving the rack teeth 84. When the rack slides longitudinally thepinion 80 is turned and this serves, by means of the gearing and theseveral shafts that have been described, to turn the worm 91.

gearingp T8 rotates bodily with the sleeve 79.

lt willfthercfore be clear that the relative movement' of the spindle 5with respect to the sleeve T9 simply serves t-ocithenincrease ordecrease.` thc spindle rotation to a certain extent. However, therelative movement of the spindle 5 is determined by the longitudinalmovementof the rack 84, which in turnis determined by the longitudinalmovement of the carriage 21 and of the cutting tool 25 carried thereby,lnasmuch as therelieving am 46 reciprocates the tool with a frequencywhich iS normally uniform, andinasmuch as the spindle 5 and the blankare given a changed rotation which is in exact proportion to thellongitudinal movement of thecarriage and the tool, it is clear that therelieving movements are effected in such relation to the blank as to bein conformity with helical teeth.

The amount of variation of the spindle 5 and blank rotation can bechanged in accordance with the degree of inclination of the helicalteeth by removing one or the other or both of the gear wheels 493 and 94and substituting other gear -wheels of dilferent diameters. The idlergear wheels 98 and 99 can be properly adjusted to mesh with suchdifferently diametered gear wheels. It is also possible to cause therelative movements of the spindle 5 to take place in either. directionin conformity .with helical teeth inclined in either direction. -ASillustrated, the machine is adjusted for cutting teeth with left-handhelices. with right-hand helices the idler gear Wheel 98 is removed andthe gear Wheel 99 is adjusted to mesh directly withthe gear Wheels 93and 94. lVhen it is desired tocut a blank with straight teeth instead ofhelical teeth, the gearing rendered ineffective, as for insta-nce byloosening the clamping screws 105, thus permitting the'rod 104 to slidefreely through the bracket 102. By loosening the clamping screws 105 itis possible to preliminarilv adjust thecarriage without affecting theposition of the spindle 5 and blank. "hen the cutter and the blank havebeen properly adj usted relatively, the handles 106 are turned toconnect the carriage with the mechanism for controlling the spindlerotation.

From the foregoing description it Will be observed that infollowinghelical teeth as described, the blank is rotated in'eachinstance through a little more or a little less than one revolution, asrequired for righthand or left-hand helices. lt will further be seen,that during each rotative movement of the spindle 5 and blank a wholenumber of relieving movements are effected.

1When cutting a blankwith undercut faces. it is necessary to vary theordinary relation between the relieving movements of the tool andtherotative movement of the blank as the cutting tool moves inward oroutward to'conform to different blank diameters. One way of varying therelation will he understood by reference to the diagrammatic Fig. 1 7.In this view 't may be considered to be a fragmentary sectional viewtaken at the .maximum radius fr o'f a cutter C having undercut faces.Underthe' F or cutting teeth control of the former and the former pin7the cutting tool 25 is at a dista-nce fr from the blank axis and is inposition to engage the point of the tooth shown and tov cut .the properreliel2 line al-ci thereon. The tooth section at a smaller radius r isshown at lf. For this radius. without special `provision being made, thetool Q5 would be in the position indicated by dotted lines at thedistance r from the blank axis. However, by reason of the inclinedcutting Jfaces on the blank. the blank tooth would not be in engagementwith the tool but would be separated therefrom by the angle m. The tool,however, would immediately start its inward relieving movementnotwithstanding the fact that the blank tooth had not yet reached it,and the result would be the cutting of an incorrect reliet line al-(l. For a still smaller radius 7" of the blank, as shown at t". the resultwould he similar except that the point of the tooth would be separatedfrom the tool by a great/er angle m, with the result that the incorrectrelief line IWL-(1 would be further from the correct relief line tlv-d.

In order to avoid the errors which would occur, as shown in Fig. '17. lvary the relationship between the relieving movements of the tool andthe rotative movement ot the blank in such a way that the tool. asconcerns its relieving movements, is always in the same position whenengaged by the front edge of the tooth. rllhis will he clear from aninspection of, Figs. 1 8 and 19. Fig. 18 shows -the tool at the sainekradius r from the blank. axis las was shown' in Fig. l?, but therelation of the relieving movement has been so changed that the blank isin position to be engaged by the point ot' the tool when the relievingmovement starts. The tooth is therefore cut with the correct relief linerZ-d- Similarly. in Fig. 19. the tool is shown at the same distance r"from the blank axis as was shown in Fig. 1T. but the relation ot' therelieving movement has been so changed that the blank is in position tobe engaged by the point of the tool when the etl'ective relievingmovement starts. The tooth is therefore cut With the correct relie'llline cil-d. It will be seen that the operation. as illustrated in Figs.17 to 19, is in no way effected by or dependent on the longitudinalinclination of the cutting faces. ln other words. it is innnaterialwhether the cutting faces be helical or straight.

l The required variations in the relationship 'between the relievingmovements ot the tool and the rotative movement of the blank can bebrought about either by changing (usually advancing) the blank move-yment or by changing (usually retarding) the tool movements. l have foundsimpler. to retard thetool movements. and this is particularly desirablewhen means are provided as herein disclosed for changing the' blankmovement to conforilnt helical teeth. The tool movements may be properlyretarded by forming the grooves 7l in the shalt 71 in accordance withthe degreeof undercut. Referring to Figs. 20 and 2l, the shaft T1 isshown provided with inclined cam ngrooves T1', and the bevel gear wheel75 is shown provided with pins 75, which are adapted to enter thegrooves 71'. F ig. ".21 is a development of` the shaft 71 showing theinclined cam grooves. With the pins 71 in the full line position shown,which corresponds to the radius r, the cam 4G is in position toimmediately start the inward relieving movement of the tool. From thedescription which has been given of the mechanism for driving therelieving cam. it will be recalled that for any given longitudinalposition of the tool the cam is ordinarily rotated at a speed exactly inproportion toithe rotative movement of the spindle and blank. When thetool is moved inward to a position corresponding to the' radius r. thenormal rotative movement of the cam is retarded by an angular distance nwhich corresponds to the angle m' shown in Fig. 17. Vllhen the toolmoves still further inward to a position corresponding to theradius if",the cam is still further retarded through an angular distance ncorresponding to the angle m shown in Fig. 17. The result of thisretardingot' the tool is to cause it to be always in the 'same positionas concerns its relieving movements when the 'front edge ot the toothreaches it. The VFact that the blank may not have the maximum radius 'I'is immaterial provided that the bevel gear wheel 75 is made to take theproper positions along the cam shaft 71. lu order that this may. beconveniently brought. about, the former is preferably constructed so tocorrespond to the radius of thc blank to be cut. lt the cutter C is tohaver a maximum radius r, the `former 26 is made with the point ofmaximum radius'at a distancel r from a given reference line, forinstance the center line'of the bolts 35, lt' a cutter D is to be madehaving a radius '1"'. then the former 2G is made with the point A olmaximum radius at` the distance r from 115 the center line of the bolts.lf a cutter E is to be made having a 'maximum radius r, then the Jformer26@ is made with its point of maximum radius at the distance r trom ythe center line of the bolts. The construc- 12o tion of the formers inthe way described in,- sures the location of 'the sliding gear wheel T5on the shaft Tl at positions corresponding' exactly to the differentradii of the blanks. lu the above manner. the pin and groove connectionbetween the sluit't Tl and the gear wheel 'servcs to vary the relievingmovement `to compensate igor the non-radial cutting faces on the teethot' the blank. ln mv -copending application, Serial No. 469,266,

. above referred to, and in my application Serial No. 323,114, ledSeptember 11, 19,19, means are disclosed and claimed for per forming alike function by varyingthe position of the relieving movements.'

A'screw 10T, which engages a nut 108 car ried by a bracket 109 dependingfrom the earriageis provided for movingithe carriage longitudinallyaloneA the bed." he screw is supported at its left-hand end in a"bearing110. which is .formed in a' bracket 111 secured to the bed. A transyerseshaft/llf-which is connected with tlie"`sci'ew 107-by" means of bevelgearing 113, is mounted in the bracket 111. At the front end of theshaft 112 is a hand wheel 114 by means of which the screw maybe turnedmanually to move the carriage. A. suitable mechanism is provided formoving the carriage automatica-llyto' 'feed the tool from Aone cuttingposition to another. This v mechanism is preferably adaptedto feed thecarriage intermittently. butaitwill be un.

derstood that as concerns certain phases of the invention l do not solimit myself inasmuch as the carriage may be moved continuously it'desired.. A transverse bearing;` pin 115 upon which is rotatablymounteda sleeve 116, is mounted in the bracket 111. "A gear wheel 117,which meshes with a gear wheel 118 on the shaft 112, is looselv mountedon the sleeve 116 near the inner end thereof. ratchet wheel 119,'isconnected with the gear wheel 117. (ear teeth 120, which mesh with agear wheel 121 secured to the shaft' 112. are formed on the sleeve 116near t-he outer end thereof. A ratchet wheel 122, which is similar tothe ratchet wheel 119, is keyed to the sleeve 116. A swinging arm 123 isloosely mounted on the hub of the ratchetwheel 122'.

A link 124,' which is adjustably connected vat its left-hand end with anoscillatingcrank arm 125,` is pivotally connected with the arm ein 123near the lower end thereof. The crank arm is secured to al transverserock shaft 126 which is mounted in a bearing 12T and which carries atits rear end a lever 128. A roller 12S), which is positioned to beengaged by a cam 13() on a `longitudinally rotatable shaft 131.l iscarried bythe lever 128 near the upper end thereof. A transverse pin132, which carries two similar ratchets 133 and 134, is mounted on the'swinging arm 123. 'lhe two ratchets 133 and 134 are adaptedrespectively to engage the ratchet wheels 119 and 122. i or out ofengagement with the corresponding wheel. ner to be presently described,and it will be seen that at each rotation thereof the arm 123 and thecrank arm 125 are oscillated.

" -124. the extent of oscillation-of the plate being adjustable bychanging the connection between the link and the crank arm: By

Either ratchet can bethrown into The shaft 131 is rotated in the matr.

means of one or the-other 'of the ratchets 133 or 134, one of theratchet Wheels 119 or 122 is turned through a Asmall angle, thusturningthe shaft 112 land the lead screw 107 and moving the carriage. 1twill be seen that the carriage' movement vis relatively great when thepawl 133 is in use, and is relatively small when the pawl 134 is in use.By selecting the proper ratchet and by adjusting the crank armconnection the desired amount of carriage movementmay be obtained.

Preferably the rotation of the spindle and of the blank is stoppedduring the feeding movement of the tool. I therefore p'ovide twoalternately acting mechanisms, one serving to rotate .the spindle andthe blank through one revolution, .or approximately one revolution, andalso serving to effect the relieving movements of thetool, and the solother mechanism serving to effect the longitudinal feeding of the tooland preferably also serving to effect other movements to bei described.

The mechanism for rotating' the spindle and the blank has already beendescribed in part, this mechanism including the transverse shaft 11, theworm 10 and the worm wheel 9. The machine lis provided with a main powershaft 135 .which is adapted to be driven in any suitable way, asfor instance, by means of a` belt on a pulley 1,36.` A gear wheel 137 isrotatably mounted'on the shaft 135. Thegea'r wheel 137 is connectible tothe shaft, 135 by ,means of a splined clutch element 138. The Agearwheel ,137 meshes with a gear wheel 139, which ,isv

lcarries a series of differently diametered gear-S146. rl`he shaft 145is connected with the aforesaid shaft 11 bymeans-of bevel gearing' 14T.1The bushiircy 143 'can be moved angularly and longitudinally on thesleeve 142 yso as to bring` the gear wheel 144 into mesh with any one ofthe differently diametered4 gear wheels 146. A spring-pressed plunger148, whichis carried by the bnsh' ing 143. is adapted to enter anyoneofd a series of apertures in the sleeve 1421 so as1u to hold the lrearwheel 144 in )roper posi-V tion to mesh with any desiredl one of thegear wheels 146. lt will be seen that by this construction thesh`aft'145 together with the shaft 11 can be drivenfrom the shaft 135 atany one of. a series of speeds.

A shoi't longitudinal shaft 1-19 is moui'ited iii alignment with themain power shaft 135. rI`he shaft 119 carries a clutch element which isadapted to be engaged b v the aforesaid splined clutch element 138 onthe shaft 135. then the clutch element is in its right-hand position asviewed in Fig. 16, it drives the gear wheel 137 and the several partsconnected therewith. When the clutch element is in its left-handposition it drives the shaft 149. A transverse shaft 15()` which issuitably mounted in bearings in the bed, is connected with the shaft 149by means of bevel gearing 151. \The shaft 15() car` ries a-worm 152which meshes with a worm wheel 153 on the aforesaid longitudinal shaft131.

In the operation of the machine. it is desirable for the sleeve 79 andfor the shat't 131 to each make one complete revolution alternatel insuccession. 1n order that the desired a ternatemovements of the sleeveand shaft lmay take place, 1 provide automatic mechanism for shifting`the clutch ele` ment 138. The mechanism used is similar in principle tothat shown and described in my Patent No. 1,273,903 for drivingmechanism, dated July 30th, 1918. The clutch element 138 is providedwith an annular groove into which fit rollers or projections on a forkedlever y154. The lever 154 is transversely pivoted on the frame and isprovided with a rollei 155 by means ot which it may be-moved. Atransverse rock shaft 156 is mounted in the traine above the forkedlever 154. The rock shalt`156 carries at its rear end an arm 157 inwhich is mounted aspring-pressed plunger 158. As shown in Fig. 16, theplunger is V- shaped at its lower end and is adapted to engage theroller 155. A lever 159, which is. secured to the rock shaft 156 nearthe front end thereof, is provided with upper and lower arms. The upperariii carries a roller 160 which is adapted to be engaged by a cam plate161. The cam plate 161 is secured to a cani drum 162 which is mounted 0nthe sleeve 79. The lower arm of ythe lever 159 carries a i'ollei'163which is adapted to be engaged by a cani plate 161. The cam plate 164 issecured to a cam drum 165 which is mounted on the shaft 1231.

f hen the parts are in the. positions shown in Figs. 6. 7 and 16 thesleeve 79 is in nio` tion and continues to turn uiitiii the cani plate161 engages the roller 16() and turns ,the level' 159 in the clockwisedirection. as viewed in Fig. 7, or in the counter-clockwise direction,as viewed in Fig'. 16. This movement forces the spring-pressed plunger158 over the top oil the roller 155 and thus tends to swing the lever15-1 in the direction t0 shift. the clutch element into position todrive the shaft 149. When the shaft 149 is thus driven, the shaft 131with the Cam drum 165 thereon is driven in the direction indicated bythe arrow in Fig. 6. This movement continues until the cam plate 16-1engages the roller 163 and swings the lever 169 in thecouiitcr-clockwise direction, as viewed in Fig. 7, or in the clockwisedirection. as viewed in Fig. 16. other words, ,the cani plate 161 servesto restore the lever to the position which is shown in the drawings. Thespring-pressed plunger 158 is again moved over the top of the roller 155and tends to move the lever 1511 iii the direction to move the clutchelenient 136 into position to drive the gear wheel 137,

Preferably, 1 do not depend solely upon the shifting of the lever 159for the timing oi the movements oi the clutch element 138. )isillustrated, the lever 154 is provided with opposite fingers 166 and 167which are adapted to be engaged, respectively, by latches 165l and 169.The latches 168 and 169 are held in engagement with'the fingers by meanset a springr member 170. Re- `tei-ring to l `i; r.,16, it will be seenthat the latch 168 serves to prevent the movement of the lever 15sttoward the left even after the arm 157 has been moved 'to its right-handposition. Similarly, the latch 169 serves to prevent the movement ott'the lever 154 toward the right even after the arm 157 has been moved toits left-hand position. A vertically slidable rod 171, which is normallypressed upward by a springv 172, is provided for releasing the latch168. The upper end ot' the rod 171 is engaged by an arm 172i which ismounted on :i short transverse rock shaft 174. The rock shaft 174carries a lever 175 near its frontend. A roller. which is adapted to beengaged by a caiir projection 176,v is mounted on the lever 175. The camprojection 176 is secured to the worm wheel 9. The cani projection 176is so positioned with respect to the cam plate 161 that the plate firstengages the roller 16() and moves [the arm 157 into position to shittthe lever 154. Subsequently, when the spindle 79 has completed thedesired revolution. the cam projection 176 engages the roller on thelever 175, thus turning,r the rock shaft and the lever 172B and/movingthe iod 171 to release the latch 168. The latch hav,- ing been released,the lever 154 turns under the action of the spring-pressed plunger 158and disengages the clutch element from the gear 137 and engages it withthe shaft 149. The latch 169 is mounted on a short trans verse rocksha'r't 177 which carries a lever 17H near its trout end. A roller,which is mounted near the upper end of the leverl 17H. is positioned tobe engaged by a cani projection 17%) on the cam drum 165.' The camprojection 179 is so positioned Withlrespect to'the main cam plate 164that the plate rst engages the roller 163 and moyes the arm 15811ntoposition to'shift the lever 154. Subsequently, when the shaft 131 hascompleted the desired revolution, the cam projection 179 engages theroller and the lever 178, thus turning the rock shaft 177 to release thelatch 169. The latch having been released, the lever` 154 turns underthe action of the spring-pressed plunger 158 and disengages the clutchelement from the shaft 149 and engages it with the gear wheel 137. Itwill be seen that by means of the mechanism described the spindle-7 9serves to stop itself after making a complete revolution and to startthe shaft 131. Similarly the shaft 131, after making one completerevolution, serves to stop itself and start the spindle 79. Thus thesetwo parts operate alternately in continuous succession.

It is desirable to'feed the tool longitudinally while out of engagementwith the blank, that is, when the-tool is opposite the groove betweentwo teeth of the blank. r1-`he blank is therefore preferably mounted inthe spindle so that at the position of stopping the tool will beopposite a groove. The grooves are helical but the spindle and the blankare si'ipplementally' turned at each longitudinal movement. Thissupplemental turning exactly compensates for the inclina tion of thegrooves and insures the stopping of the blank with a groove opposite thetool.

Preferably the tool is withdrawn at the time of each longitudinal'movement, the

former pin also being withdrawn from en' Such wlthgagelaent with theformer. drawal is effected by mechanism operated by the shaft 131, thewithdrawal being thus properly timed with respect to the feedingmovement. An abutment 180, which is engaged by the upper end of a lever181, is associated with the slide 24s The lever 181 is longitudinall \vpivoted to the carriage 21. rlhc lower end of the lever is providedwitha roller which is adapted to be 'engaged by a cam plate 18;). 'lhe camplate 182 is mounted on a cani disk 18B which is secured to the shaft1251. .\t the beginning of the. rotation of the shaft 131 the cam plate182 engages the roller on the lever 181 and swings it in aconnter-clm-kwise direction` thus moving the abutn'ient 18() togetherwith the slide 21 toward the front.. ln this way the tool 25isa'vitlnlrawn from the blank and the former pin 27- is withdrawn fromthe erative positions. It will be seen that by thus withdrawing theformer pin from the former at the time of longitudinal movement, I avoidan)7 difficulties incident to forcing the former pin along the lformervwhile in contact therewith. If the formerpin were maintained in contactwith the former at all times difficulty would be experienced ineffecting the longitudinal movement. particularly at places where thecontour of the former is sharply inclined.

Preferably the former pin is restored to engagement with the former bya- 1elatively slow movement with a minimum of pressure, so that therewill be no tendency to 80 bend or distort the pin or to secure unevencontact between the pin and the former. For this purpose, I provide amechanism for returning the carriage that is entirely independent in itsoperation from, the'mecha nism for withdrawing it. The before men-Ationed abutment 180 is not connected directly to the slide 21 but isconnected to a second slide 18-1 which is transversely movableindependently of the first slide 21. Springs 185 are interposed betweenthe slide 184 and the carriage 21 and these .springs tend to. move theslide 184 rearward, thus holding the abutment 180 at all times inengagement with the lever 181.

The two slides 24 and 184 are ordinarily connected by a lock. As'shownmost clearly in Figs. 7, 8 and 12, the lock includes a plate 186.located in a recess in the top of the slide 24. AThe plate is providedwith a-boss 109 which projects downward through a. slot in the slide`and threaded into this boss is a Vertical stud 187."The stud 187 extendsthrough and closely fits an aperture in the Slide 184. 'lwo smallbell-crank levers 188 areloli pivoted to the slide 181. The levers 188are provided with horizontal upper arms which engage a collar on thestud 187. 'lhe lower ends of the levers are adapted to be engaged by atapered cam bushing 189 which is ver- 110 tically movable on the stud.\Vhen the bushing 189 isin itslowerposition, as shown, the levers 188are forced ont-ward` thus drawing the stud 187 do\vn\\ard and forcingthe plate 186 into clamping engagement wththe slide 115 24. ln this waythe slide 21 is firmly connected with the slide 184. When the bushing189 is in its raised positiom'the levers 188 swing inward. thuspermitting the stud 187 to move upward and release the plate 186 130vfrom its clamping engagement with the slide 21. forkedf lever 190`having projections engaging slides or notches in the bushing. I isprovided foeanoi'ing the'bushilig 189. The

level' 19t) is secured tout longitudinal rock 125 shaft 191 which -ismounted in bearings `in the carriage :21. A lever 192 is' connected tothe lever tilt). The lewer 192 is provided with a roller which isadapted to be engaged by cam plates l9 apd 1% tllatearef'sctlrd 130 to aearn disk 195 mounted on the shat't l?,

It will he seen that as the shait 1?1 rotates.v

the cam plate lfl' engages the roller on the, lever 192. thus moving thelever '19() and the cam hashing 189' upward to release the loelt.Subsequently the roller is engaged hy the cam plate 194. thus moving theam bushing lttl'oownward to re-engage the loelt.

l l have already stated that a supplemental meehanism is provided forreturning the slide afterv it has heen withdrawn in the 'manner beforedeserihed, iret'erahly. in order that the -supplemental turningmeehanisni may operate without heing at- 'erled in any way hy the returnmovement ot the slide 11%. and in order tnrther that. the slide 2l mayhe returned with a ruiniminn ot' etl'ort. l provide a supplemental meansfor supporting the slide 'il alter it has heen unlocked from the slide1&4-, s illust ated, the earriage 2l is provided neel its front and rearwith transverse pivot pins 1% and 19T. rl`he earriage is slotted adjaeenty the pins. and in these slots are posh tioned arms 10H and 19)respeetively pivoted on the. said pins. llhe arms are respeetivelyprovided with rollers 201i and 2111 whieh are adapted to engage thehottom ot the slide 2. The arms are eonneeted hy pivoted linlts 202. andthese lin'l-zs in turn are eozmeeted h" a transverse volte 2015. theyoke 202i is provided with slots or notches in whieh lit pivot hosses21H' projeeting upward from the lever 191i. The result is that when thelever 19() swung upward to release rthe loelt. the arms 198 and 15M) areswung in a eloehwise direction. thus swinging` the rollers 211i) and 201upward so to lil'ti the slide 2l otl4 from the slide, 1M and support it.indepemlently. The aetual raising o'lu the slide may he hut a fewthousandths ot an ineh, toil springs 205 are provided t'or returning,the slide -l rearward as soon as it has heen released h v the loelt andelevated hy the rollers. lret'er- `l ahi): these springs are loeated inlong transverse vizylindrieal apertures 206 in the slide i241. rl`hesprings ahut at` their rear ends against plugs 20T threaded into theapertures. and at their Vt'ront ends ahnt against heads 20h ontransverse rods i205). yl`he rods 2119 extend through eentral openingsin the pings 90T and are eonnerted at their rear riadsl wsth lu'aeltets22.11) on the earrilage Z1.l l reterahly theheads 20H :ire in the torniol pistons and the forward yparts ot' the 'apertues 20h eoustiluteeylinders 211 in whieh the heads Elin lit and move. .t eastino 212.whieh provided with a` transverse pas ageway 213, is seeured to theslide 2l. rl`he passageway lill eouununieates at is ends with eylindersall... i'luid reservoir 2li is also Jformed in the easting 21;). .tresti'ieted aperture whieh is prel'erahly eontrolled hy an adjustahleneedle valve 21h. leads trom the passageway 211 into the reservoir Huehtendeuijv. however. is resisted h v the engagement ot the pistons 20Swith the liquid in the eylinders. This engagement Vl'orees the liquidout o'l' the eylinders into the passageway J1-"l and thenee into thereservoir .lll through the restrieted aperture 215. 'the liquid ran passthrough this aperture Vonly' relativelv slowly. and thus the returnniovenient oti the slide is made to take plaee very slowly, When theslide is moved duieltly forward at the time o1' next leerling. the herirvalvey :21T opens to permit the liquid to flow Atrom the reservoir ,ilhaek to the passageway i213 and the eylinders 211. The

slow return movement eauses the tormer pin to enf ige the former gentlyand with a minimum loree. so that there is little or no tend-v eney tohend or delleet the parts.

It, will he noted that the several eams 131), ltlQ. 11)?) and 194 are sopositioned in relation to each other that the operations whieh theyrespeetively eontrol take plaee in the tollowing order. First the twoslides 181 and :2l are moved haeltward in unison, they' being stillvloeked toeether. Then the slide 2l is unloelted Troni the slide '1H-1and is at the same time elevated on the, rollers 2li() and 201. At orahout the same time the. carriage is moved longitudinally to teed thetool to a new eutting position. rthen the slide 181 is permitted toreturn to its normal position. ln the mean time the slide 241 is heingmoved slowly rearward under the control of the springs Q05 and the iluidregulating meehanism. After the eompletion o'l the return movement otthe. slide 2l, the rollers 2li() and 201 are lowered and the slide isagain loi-lied lo the .slide 134,

l provide a lever 2lb. whieh 'is seeured to the roelt shal't` lill. tormanually releasing the slide 2l ll'rom the slide Inl. wreneh 21h".y asshown in Fig. n. is provided tor moving the lever 21H..` ltwill he seenthat the operator. hy moving the lever 21H. ean tnrn the roel; sha1't.thus raising the ram sleevo'lHS) and releasing the` Voelt. segmentalgear Q11), whieh is pivoted to the, earriage and meshes with a raelt 21)seeured to they slide. is provided l'or manually moving thel slide iltorward. hand lever 221 is eonneeled with the segmental gear 211). Itwill he seen that hy lowering or `aising the handle the slide 'I1-leanhe moved forward or hael-:ward as desired.

lt is heliev'ed that the general operation l in succession.

sired contour and. in the case of an undercut cutter, having the desiredrelation to the cutter radius, as already explained, blank is put inplace. this blank having been previously grooved and roughed out in anyusual or preferred manner. 'l`he gearing T8 is adjusted in accordancewith the degree otinclination ot the helical tceth on the blank and thegearing .G6-57 is adjusted in accordance with the number ot teeth on'the blank. By means ol the hand wheels` -lfll and ll-l, the tool isadjusted transversely and longitudinally into engagement with the blankat the right-hand end thereof. 'l`hen the machine is started, thespindleTS) Vand the operating shaft 131 operating alternately During therotative movement of the lblank relieving movements of the tool areeffected as described, thus cutting the desired relief on the teeth ofthe blank. After one complete revolution of the blank the rotativemovement of the spindle is stopped and also the relieving movements ofthe tool, l The carriage is then fed longitudinally toward the lleft,the blank turning slightly in conformity with the helical teeth.

. Just prior to the longitudinal movement the tool slide is withdrawn,thus withdrawing the tool from the blank and the former pin from theformer. After the longitudinal movement, the tool slide is moved slowlyin the opposite direction, thus gently returning the former pin to theiormer which isv engaged at a. new position. The tool assumes acorresponding position with respect to the blank. After this movement ofthe tool and formerpin the blank is again rotated through one revolutionand these movements are repeated alternately in succession until theblank is completely formed.l The relieving movements ofthe tool arechanged in accordance with changes in diameter already described, tocompensate for the non-radial cutting faces on the teeth of the blank.

Modifications in the machine and in the arrangement and location ofparts'may be made within the spiritI and scope ot my invention, and suchmodifications are intended to be covered by the appended claims.

What I claim is: I

I.`In a relieving machine yfor operating on a blank having teethprovided with nonradially arranged cutting faces', the combinationcompri-sing a cutting tool,` means for effecting feeding movementsbetween said tool and the blank, means for efecting relieving movements'of the tool, and means for varying the relieving movements at dif-`:ferent blank diameters .to compensate for thenonradial tooth faces onthe blank.

2. ln a relieving machine for operating on a blank having teeth providedwith nonradiallv arranged cutting faces.the combination comprising acutting tool, means i'or operating said tool to torni a cutter adaptedto cut a predetermined non-rectilineal' contour.

means tor effecting relieving movements of' said tool` and means forvanving the relieving movements at different blanl: diameters tocompensate for, the non-radial cutting faces on the teeth ot' the blank.

3. ln a relieving machine for operating on a blank having helical teethprovided with non-radially arranged cutting faces, the combinationcomprising a cutting tool, means for effecting feeding movements betweensaid tool and the blank. means fdr effecting relievingmovements ol thetool, and means tor automatically vaiving the relieving movements atditlerent blank diameters to compensate for the non-radial cutting faceson the blahk.

4. ln a relieving machine for operating on a blank having lhelical teethprovided with non-radially arranged cutting faces,l the combinationcon'iprising a .cutting tool; means for operating said tool to `form acutter adapted to cut .a predetermined nonrectilinear contour, means foreffecting re` lieving movements of said tool, and means for varying therelieving movements at dilferent blank diameters to compensate for thenon-radial cutting faces on the teeth of the blank.

5. In a relieving machine for operating on a blank having undercutteeth, the combination comprising a cutting tool, means for operatingsaid tool to cut a` predetermined contour, means for effecting relievingmovements of the tool, and means for automatically var vingthe relievingmovements at -difi'erent blank diameters to compensate for the undercutteeth.

t5. In a relieving machine for operating on a blank having undercuthelical teeth, the combination i means for effecting feeding movementsbecomprising a cutting tool,

tween the tool and the blank to cut the latter to different diameters,means forketi'ecting relieving movements ofi' the tool, arid. meansytorvarying the relieving movemenbat diftere'nt blank diameters tocompensate for the undercut teeth.

7. In a relievingmachine for operating lon.

a blank lhaving teeth provided with nonradially arranged cutting faces,the combination comprising a cutting tool, means for' ei"- fectingfeeding movements between the oo-l and the blank,l means for guiding thecutting tool to cut a for effecting relieving movements ofthe .toolrelative to the blank, andv means for varymg blank diameters tocompensate tortille nonradial cutting vfaces `von the teeth.

predetermined contour, meansv the relieving movements atfditferent s. lna reiieving machine for opeiatingf` on a blank having teeth providedwith nonradially arranged cutting faces. the com bination comprising acutting tool, automatically operating means for governing said tool tofor a cutter adapted to cnt a predetermined contour` means for effectingrelieving movements of the tool in conformity to the teeth on the blank.and means tor varying such relieving moveiiientsvat different blankdiameters to compensate for the non-radial cutting faces on the teeth.

t), lii a relieving machine for opeiatii'ig on a blank having helicalteeth provided with non-radially arranged cutting faces. the combinationcomprising a cutting tool,

means toi' eti'ectiiig feeding movementsl lietivcen said tool and theblank. automatically operating means for ell'ecting relieving movementsof the tool iii conformity with tlie helical teeth ou the blank, andmeans for varying the relievingr movements at ditterent blank diametersto connensate for the nonradial cutting faces .'.i the teeth of theblank.

lll. ln a relieving machine for operating ou a blank having helicalteeth provided with non-radially arranged cutting faces, the combinationcoinprising a cutting tool. automatically operating means for etlfectingfeeding movements between said tool and the blank to form a cutter witha predeten mined contour (littering from a straight line. means foreffecting relieving movements of the tool in conformity with the helicalteeth ou the blank. and means for varying the relieving movements atdi'tterent blank dia'iieters in conformity with the nonradial cuttingfaces on the teeth.

l1. ln a relieving machine for operating on a blank having teethprovided with nonradially arranged cutting faces. the conibination witha cutting tool and means for feeding the tool relatively to the blank,ot means for ettecting an oscillatory transverse movement of the cuttingtool to obtain a relieving cut, and means for so moi'lifying' theoscillatory movement at ditferent blank diameters as to compensate forthe. nonradial tooth faces on the blank.

l2. ln a ielieving iiiacliiue for operating on a blank havingteethprovided with nonradially arranged cutting'faces, the combination with acutting tool and means for intermittently and longitudinally feeding thetool relatively to the blank, of

means for effecting an oscillatory transverse movement of the cuttingtool to obtain a relieving cut` and means for so n'iiidifying theoscillatory movement at ditierent blank diameters as io compensate forthe non-ra dial tooth faces on the blank. l

13. ln a relieving machine for operating on a blank having helical teethprovided with non-radially arranged cutting faces,

l-l. In a relieving machine for operating on a blank having teethprovided with nonradially arranged cutting faces. the combination with acutting tool. means for intermittently and longitudinally toolrelatively to the blank. and means for withdrawing the tool fromengagement with the blank prior to each feeding movement and forrestoring the tool into operative position relative to the blank aftereach feedingmovement. of means for ett'ecting an oscillatory transversemovement of-the cutting tool to obtain a relieving cnt and means for somodifying the oscillatory movement at ditl'erent blank diameters as tocompensate for the non-radial tooth faces on the blank. i

l5. ln a. relieving machine for operating on a blank having teethprovided with nonradially arranged cutting` faces. the combination witha cutting tool. means for intermittently and longitudinally feeding thetool relatively to the blank. and means for4 effecting transversemovement of the tool to permitthe feeding movements, ot' means forcti'ecting an oscillatory transverse movement of the cutting tool toobtain a relieving cut and means for modifying the oscillatory movementat different blank diameters to compensate for the non-radial toothfaces on the blank.

lo. In a relieving 0n a blank having;- with non-adially arranged cuttingfaces, the combination with a cutting` tool, means for intermittentlyand longitudinally.feeding the tool relatively yto the blank,v and meansfor withdrawing the tool from en` gagement with the blank prior to eachfeeding movement and for restoring the tool machine for operating intooperative position relative to the blank4 after each feeding movement,of means for ettecting oscillating transverse movement of the cuttingtool to obtain a relieving cut in conformity to the helical teeth, andmeans for modifying the oscillatory movement at different blankdiameters. to compensate for the non-radial tooth faces on the blank.

1T. In a relieving machine for operating.-

on a blankhaving helical teeth provided with non-radially arrangedcutting vfaces, the combination with a. cuttlng toohmeans forintermittently and longitudinally-feed-' mg the tool relatively to theblank, and,I

means for effecting transverse movement ot feeding the vhelical teethprovided v the tool to permit the feeding movements. of means foreffecting an oscilli'itorjY transverse movement ofthe cutting `tool toobtain a relieving cut in conformity to the helical teeth, and means formodifying the oscillatory movement at different blank diameters tocompensate for the non-radial tooth faces on the blank.

18. In a relieving machine for operating on a blank having .teethprovided with nonradially arranged cutting faces, the combinationcomprising a cutting'` tool. means for effecting fee-ding movementsbetween the tool and the blank. means comprising a pin and a former forguiding the cutting tool to cut a predetermined cmtourfmeans for varyingthe movements of the cutting tool to relieve the teeth on the blank. andmeans for varying the relieving movements at different blank diametersto compensate for the non-radial cutting faces on the teeth. i

lii. ln a relieving machine, :the combination comprising a rotatablespindle adapted to carry a blank having teeth provided withnon-rzulially arranged cutting faces, a cutting tool. means for eectingrelative feedingr movement between the tool and the blank longitudinallyof the latter, means comprising a pin and former for moving the toolinward or outward during the feed# ing movement to cut the blank with'different diameters. means for effecting relieving movements of thetool in timed relation to the blank rotation, and means for varying therelieving movements of the tool at different blank diameters inconformity Wit the non-radial tooth faces on the blank.

2u. In a relieving machine for operating on a blank having helical teethprovided with non-radially arranged cutting faces, the combinationcomprising a cutting tool, means for effecting longitudinal feedingmovements between said tool and the blank,l

means comprising a pin and a former for guiding the tool to cut apredetermined nonrectilinear contour, means forvarying the movements ofthe cutting tool to relieve the teeth on the blank, and means comprisinga cam member for varying the relieving movements at different blankdiameters to compensate for the non-radial cutting faces on the 'teetli.

21. ln a relievingmachine. the-combination comprising a rotatablespindle adapted to 'carry a blank having helical` teeth providedwithnon-radially arranged cutting faces. a cutting tool, meansforeffecting relative feeding movement between the tool and the blanklongitudinally of the latter, means comprising a pin and former formoving the tool inward and outward during the feeding movement to cutthe blank with different diameters, means for effectingrelievingmovements of the tool in timed relation to the blank rotation. means forvarying the relation between the relieving' movements of the tool andthe rotative movement of the blank in conformity with helical teeth onthe blank. and means for viii-ying the relieving movements of the toolat different blank diameters in conformity with the nonradil tooth faceson the blank.

In a relieving machine, the combinanation comprising a rotatable spindleadapted to carry a blank having teeth provided with non-radiallyarranged cutting faces, a

carriage movable longitudinal-ly of the spindle axis. atransverselymovable slide on said carriage, a cutting tool carried by the slide,mechanism for moving the slide and the 'tool transversely as thecarriage moves longitudinally so to cut the blank with a predeterminedcontour, mechanism for effecting relieving movements of the toolrelatively to the slide in timed relation to the blank' rotation. saidAmechanism serving to accurately time the relieving movements not-,j

withstanding the inward or outward niove" relative to the blank to4permit the longi-l tudinal feeding movements, means comprising a pinand a former for guiding the cutting tool to` -cut a predeterminedcontour, means forV effecting relieving movements,

and means for varying the relieving Inove-l ments at different blankdiameters to com pensate for the non-radial cutting faces on the teeth.

24. In a 'relieving machine for operating on a blank having helicalteeth provided with nonaadially arranged cutting faces, the combinationcomprising a cutting tool, means for effecting longitudinal feedingmovements between the tool and the blank, means for varying thetransverse position of the tool relative to the blank to permit theloiwitudinal feeding operation, means comprising a pin and a foimer forguiding the cutting tool to cut a predetermined 'contoiir, means foreffecting relieving movements of the tool relative to the blank. andmeans for varying the relieving movements at different blank diametersto compensate for the non-radial cutting faces on the teeth.

25. In a relieving machine for operating on a blank havingteetb providedwith nonradially arranged cutting faces. the combination comprising acutting tool, means for effecting intermittent feedingr movements' l ona blank having' teeth provided with non- 'adially arranged enttintrlaees. the 'eombination comprising' a vatting tool. means t'or"Yeffecting.T intermittent longitudinal feeding' movements between thetool and the blank. means 'for .vithda'awintr the tool fromengagei'nentwith the blank prior to eaeb reed ing movement and for restoring' thetool into operative position irelativlv to the blank after each feedingmovement. a pin and a former member tor guiding the tool to eut arn'edetermined eontour. means for effecting relieving' movementsl ol'the tool relative to the blank. and means lor var ving the relievingYmovements to rompensate toi' the inni-radial cutting tares on the teeth.

2T, ln a relieving machine 'l'or operating' on a blank having heiiealteeth provided with non-ra liadlj.v arranged rotting' t'aees. theCombination romprisingg a euttingf tool. means for ritter-tingintermittent longitudb nal teeding' movements between .said tool and,v

thefblank. means 'lor withdrawing the tool trom. engagement with theblank prior to earh teei'lingf movement and t'o' restoring' the toolinto operative position relative to the blank. means eomprising a pinand a lormer tor guiding the tool to ent a predetermined Contour. meanstor etl'ertin} r relievinjg movements ot'.tlie tool in eonl'ormitv withthe hyelieal teeth on the blank` and means tur var viug1r the relieving'movements at ditlerent blank diameters to compensate for the non-radialentingl' t'aees 'on the teeth.

"2H, ln a relieving machine l'or operating' on a blank having' teethprovided n'ith non radiallj.' arranged vatting' Jfares. the eombination.eomprisiug a enttiin; tool. means 'l'or eti'erting intermittentlongitudinal feeding movementsv between the tool and the blaruk.

.means tor varying' the transverse position of the tool relativi 'tothe-blank to permit the longitudinal 'feeding' movements. meansromprising' a pin and a formel" for guiding the Hitting lool to rut apreilelermined rontour. means l'or ell'ertingl relieving movements. andmeans lor var'vintg' the relieving movements,at'dil'lerent blankdiameters to' rompensate t'or the noiii'znlial enttingr 'tai-es on theteeth ot the blank. i

2). ln a relieving marhine for operatiirgg on a blank having..y heliealteeth provided with, non-radially arranged euttingg' t'af'es. theCombination t'omprisingn a entting tool.

mains for e looting intermittent longitnninal feeding movements betweenSaid tooland the blank. means eonrprisnrg'a pin and a. torner torraiding the tool to ent a predetermined eontonr. means for varving themovements 'otI the cutting.' tool to relieve the teeth on 'the blank.and means for varying the relieving movements to eoxnpenaate for thenon-radial ruttine' tates on the teeth in aeeordanee 'ivith thevariations in diameter ol the blank.

Slt). ln a relieving machine tor operating on ya blank having he i"alteeth Y-pren'ided with non-radially arranged cutting r'aces. thef'ombination eomprising.r a cutting' tool. means tor eleeting'intermittent longitudinal 'feeding movements between said tool and theblank` means rompt-ising:- a pin and a 'former for guiding' the tool toeut a predetermined non-reetilinear rontour. means fuor varying' themovements of the cutting: tool to relieve the teeth on the blank. andmeans lor vanvinp; the relieving' movements to eompensate tor tbe nou-'adial rotting faves on the teeth in aeeordaure with/the variations indiameter of the blank. 1

Ill. ln a relieving maehine for bperatingf on a blank havingY helir'alteethV provided 'with non-radiallj,Y arranged ruttinglv fares. theeombinatiou comprising a rutting tool, means 'tor elieeting intermittentlongitudinal feeding movements between the tool and the blank. means lorvar ving; the transverse position ot the tool relative to the blank topermit the longitudinal teeding' movements.. means romprising' a pin anda lormor tor guiding' the rntting tool to ent a predeterminednon-reetilinear eontonr` meansfor etl'erting' relievingA movements. andmeans for varving ther relieving movements to eompens-tate at dill'erentblau-k diameters l'or the non-radial vatting' fares ou the teeth.

52. ln a. relieving; maehine Afor operating on a blank having' heliralteeth provided with nonlrznliallv arranged eutting' fares..

the rombiuation eomprising' a ('uttingf tool` means 'tor ell'ertiugjintermittent longitudi nal feeding' movements between said tool and `theblank. means tor \vitlnlra\vin;' the tool t'rom engagement with theblank prior to earh leerling; 'movement and tor restoring the tool intooperative position relative to the blank. means eomprising a pin and alor-mer los' guiding the tool to vn a prede4 terminrd non-rettilineareonlour. means tor ell'erting relieving' movements ol' the tool ineontorinitj: with the h eliral teeth on the blank. and `means forvarying the relkn'inglA movements at dill'erent blank diameters to.rompensate tor the non-rmlial ru'ttinrr fares means for effectinglongitudinal feeding movements between the tool' and the blank, meansfor varying the transverse position of tlieinoll relative to the blankto permit the longitudinal feeding movements, means comprising-"zil pinand a former for guiding the cutting `tool to cut a predeterminedcontour, means for effecting relieving'move ments, and means for/varyingthe relieving movements at different blank diameters in accordance withthe contour of the former to compensate for the non-radial Acuttingfaces on the teeth.

34. In a relieving machine for operating on a blank having helical teethpiovided with non-radially arranged cutting' faces, the combiiiat-ioncomprising a cutting tool,

' means for effecting longitudinal feeding movements between the tooland the blank, means for varying the transverse position of t-he toolrelative to the blank to permit the longitudinal feeding movements,means comprising a pin and a former for guiding the cutting tool to cuta predetermined noiirectilinear contour, means for effecting relievingmovements, and means for varying the relieving movements in accordancewith the contour of the former to compensate for the' non-radialIcutting faces on the teeth. i 35. In a relieving machine for operatingon a blank having teeth provided with nonradially arranged cuttingfaces, the combi-v nation comprising a cutting tool, means for effectingintermittent longitudinal feeding lmovement of the cutting tool relativeto the cutter blank, means for withdrawing the tool from engagementwiththe blank prior to each feeding movement and for restoring the-toolinto operative position relative to the blank after each feedingmovement, means for effecting an oscillatory transverse movement of thecutting tool-to obtain a relieving cut, and means comprising a pin andam groove connection for so modifying the. oscillatory, movement of thetool as to compensate for the non-radial tooth faces on the blank.

36. In a relieving machine for operating on a blank having helical teethprovided with non-radially arranged cutting faces, the combinationcomprising a cutting'tool, means for effecting intermittent longitudinalfeeding movement of the cutting tool relative to the cutter blank, meansfor withdrawing `the ltool from engagement with the blank prior to eachfeeding movement and for re- I'storing the tool into operative positionrelative to the blank after each feeding movenient, ineans'for effectingrelieving movements of the toolin conforniityto the helical teeth on theblank, and means comprising a pin and-groove connection' for somodifying lthe relieving movement. of thetool as to compensate for thenon-radial toth faces on the blank.

3T. ln a relieving machine for operating on a blank having helical teethprovided with non-radially arranged cutting faces, the combination witha cutting tool, and means for effecting intermittent loiigitiidinalfeeding movementof the cutting tool relative to the blank, of means forwithdrawing the tool from engagement with the blank prior to eachfeeding movement and for restoring the tool into operative positiontherewith after each feeding operation,-

means for effecting relieving movements, andmeans comprising a shafthaving camgiooves formed therein for so varying the relieving movementsas `to compensate for the noii-radial cutting faces on -the blank.

438. In a relieving machine for operating on a. blank having helicalteethprovided with non-radiali)r arranged cutting faces, the combinationwith a cutting tool, and means for effecting intermittent longitudinalfeeding movements of the cutting tool relative to the blank of means forwithdrawing the tool from engagen'ient with the blank, of meanscomprising a relieving cammember driven. by a ti'aiisversely-mounted camshaft for effecting relieving movements of the tool relativelyto theblank in confoiniity to the teeth on'the blank While compensating .suchmovements for the non' radial cutting faceson the teeth of the blank.

40. In a relieving machine. the combination with a rotatable spindleadapted to, carry a blank having helical teeth provided withnon-radially .arranged cutting faces, a cutting tool, and means foreffecting feeding movements ietween the tool and the'.

blank` of means comprising a relieving cam member driven by atransvcrsely-mounted cam shaft for effecting relieving,movements of thetool in conformity to the helical teeth on thc blank and forcompensating such movements in accordance with the non-i'ai dial cuttingraces on the blank.

41. ln a relieving machine, the combination with la rotatable spindleadapted tocarry a blank having teeth providedwith Inon-radially arrangedcutting faces, a cuit-i' relatively to the blank, and means foreffectingtransverse movements of the tool to iso

